I usually hunt with O/U's - so all the safeties are on top of the tang-at least on Browning's/ easy to reach / but I rarely have the safety on.
Like OneOunce, when I'm walking the gun is broken open - and if its a surprise flush - plant my feet, focus on the bird only, move the gun forward - closing the gun and mounting the gun ...and execute the shot. If the dogs are alert, and I'm the "Hot" gun or 1st shooter / I will have the gun closed / muzzle up / finger up on receiver above trigger guard - never inside trigger guard or on trigger ---plant my feet, mount the gun, find dogs in peripheral vision, (hard focus on bird, never on barrel, and execute the shot).
My typical gunmount - is a "rectangle" - where the gun goes straight out, straight up --and straight back to my shoulder ( focus on bird, finger on trigger and preset the trigger (take slack out), and execute the shot).
If I choose to hunt with a semi-auto or a pump gun ....the action is open / or back on a pump ( shell is in receiver / but not in chamber ) - and safety is not engaged. If an unexpected flush happens / I close the action - putting a shell in the chamber ...mount the gun and execute the shot. If I'm the Hot gun / dogs are alert --- I will close the action / muzzle always up at that point ( gun at port arms ) - as long as the footing is secure.
If the footing is not clear and unobscured ... then I will always leave the action open until I can plant my feet vs walking where I might stumble on uneven ground with a round in the chamber. I don't rely on a safety lever to "bail me out" ....if I were to trip or fall.
But the safety on top of the tang / like with a Browning BPS pump is another reason I like that gun - if I choose to use the safety for some reason / its there and easy to reach. ( but I think the action open / is frankly better ) ---and if you practice closing and mounting the gun in a fluid motion / its a quick move.